Dual-channel air-pulse optical coherence elastography for frequency-response analysis.

Microliter air-pulse optical coherence elastography (OCE) has recently been proposed for the characterization of soft-tissue biomechanics using transient, sub-nanometer to micrometer-scale natural frequency oscillations. However, previous studies have not been able to provide real-time air-pulse monitoring during OCE natural frequency measurement, which could lead to inaccurate measurement results due to the unknown excitation spectrum. To address this issue, we introduce a dual-channel air-pulse OCE method, with one channel stimulating the sample and the other being simultaneously measured with a pressure sensor. This allows for more accurate natural frequency characterization using the frequency response function, as proven by a comprehensive comparison under different conditions with a diverse range of excitation spectra (from broad to narrow, clean to noisy) as well as a diverse set of sample response spectra. We also demonstrate the capability of the frequency-response analysis in distinguishing samples with different stiffness levels: the dominant natural frequencies increased with agar concentrations (181-359 Hz, concentrations: 1-2%, and maximum displacements: 0.12-0.47 µm) and intraocular pressures (IOPs) for the silicone cornea (333-412 Hz, IOP: 5-40 mmHg, and maximum displacements: 0.41-0.52 µm) under a 200 Pa stimulation pressure. These frequencies remained consistent across different air-pulse durations (3 ms to 35 ms). The dual-channel OCE approach that uses transient, low-pressure stimulation and high-resolution imaging holds the potential to advance our understanding of sample frequency responses, especially when investigating delicate tissues such as the human cornea in vivo.

Feasibility analysis of China's medical insurance coverage of assisted reproductive technology.

There are millions of patients experiencing infertility in China, but assisted reproductive technology (ART) is performed at the patient's expense and is difficult to afford. With the sharp decline in China's birth rate, there is a growing controversy over the inclusion of ART in medical insurance (MI). This study aims to explore the feasibility of ART coverage by MI for the first time. We obtained basic data such as the prevalence of infertility, the cost of ART, and the success rate in China with the method of meta-analysis and consulting the government bulletin. Then, we calculated the number of infertile couples in China and the total financial expenditure of MI covering ART. Finally, we discussed the feasibility of coverage, and analyzed the population growth and economic benefits after coverage. According to our research results, it was estimated that there were 4.102-11.792 million infertile couples in China, with an annual increase of 1.189-1.867 million. If MI covered ART, the fund would pay 72.313-207.878 billion yuan, accounting for 2-6% of the current fund balance, and the subsequent annual payment would be 20.961-32.913 billion yuan, accounting for 4-7% of the annual fund balance. This was assuming that all infertile couples would undergo ART, and the actual cost would be lower. The financial input‒output ratio would be 13.022. Benefiting from the inclusion of ART in MI coverage, there would be 3.348-9.624 million new live infants, and 8-13% newborns would be born every year thereafter, which means that by 2050, 37-65 million people would be born. Due to its affordable cost, high cost-effectiveness and favourable population growth, it may be feasible to include ART in MI.

Relationship between maternal ABO blood groups and pregnancy outcomes: a retrospective cohort study in Dongguan, China.

The purpose of this study was to study the relationship between maternal ABO blood groups and pregnancy outcomes. A total of 29,658 couples in Dongguan were selected as the research subjects. We obtained data on ABO blood groups and pregnancy outcomes and explored the relationship between them through log binomial regression and survival analysis. Compared to mothers with type B blood, the RR of foetal stillbirth in mothers with type A blood was 2.87 (95% CI: 1.70, 4.85), and compared to mothers with type O blood, the RR was 1.72 (95% CI: 1.16, 2.55). Compared with foetuses of other three blood type mothers, foetuses of A blood type mothers have a higher median birth weight (P = 0.011). Other pregnancy outcomes, including preterm birth, macrosomia, caesarean section, multiple births, birth defects, low birth weight, foetal sex, gestational days, birth length, and APGAR score, were not significantly different. The relationship between maternal ABO blood type and pregnancy outcomes was not affected by paternal blood type. More studies are needed to confirm these results.

What is already known on this subject? The relationship between blood type and disease is being increasingly studied. With regard to the relationship between maternal blood type and pregnancy outcomes, some studies have focused on people undergoing in vitro fertilisation. There are few reports on healthy women.What do the results of this study add? Compared to mothers with type B blood, the RR of foetal stillbirth in mothers with type A blood was 2.87 (95% CI: 1.70, 4.85), and compared to mothers with type O blood, the RR was 1.72 (95% CI: 1.16, 2.55). Compared with foetuses of other three blood type mothers, foetuses of A blood type mothers have a higher median birth weight (P = 0.011).What are the implications of these findings for clinical practice and/or further research? This study is the first to explore the relationship between blood type and pregnancy outcomes in healthy women.These results can provide some clues for the study of the mechanism of pregnancy outcomes.

Corneal Surface Wave Propagation Associated with Intraocular Pressures: OCT Elastography Assessment in a Simplified Eye Model.

Assessing corneal biomechanics in vivo has long been a challenge in the field of ophthalmology. Despite recent advances in optical coherence tomography (OCT)-based elastography (OCE) methods, controversy remains regarding the effect of intraocular pressure (IOP) on mechanical wave propagation speed in the cornea. This could be attributed to the complexity of corneal biomechanics and the difficulties associated with conducting in vivo corneal shear-wave OCE measurements. We constructed a simplified artificial eye model with a silicone cornea and controllable IOPs and performed surface wave OCE measurements in radial directions (54-324°) of the silicone cornea at different IOP levels (10-40 mmHg). The results demonstrated increases in wave propagation speeds (mean ± STD) from 6.55 ± 0.09 m/s (10 mmHg) to 9.82 ± 0.19 m/s (40 mmHg), leading to an estimate of Young's modulus, which increased from 145.23 ± 4.43 kPa to 326.44 ± 13.30 kPa. Our implementation of an artificial eye model highlighted that the impact of IOP on Young's modulus (ΔE = 165.59 kPa, IOP: 10-40 mmHg) was more significant than the effect of stretching of the silicone cornea (ΔE = 15.79 kPa, relative elongation: 0.98-6.49%). Our study sheds light on the potential advantages of using an artificial eye model to represent the response of the human cornea during OCE measurement and provides valuable insights into the impact of IOP on wave-based OCE measurement for future in vivo corneal biomechanics studies.

History of induced abortion and the risk of preterm birth: a retrospective cohort study.

OBJECTIVES: To explore the relationship between a history of induced abortion and follow-up preterm birth. METHODS: We performed a retrospective cohort study of 27,176 women aged 19 to 48 years old in the city of Dongguan. Participants were divided into two groups according to the history of induced abortion. We used log-binomial regression to estimate adjusted risk ratios of preterm birth (gestation at less than 37 weeks) and early preterm birth (gestation at less than 34 weeks) for women with a history of induced abortion. Four models adjusted for different baseline data were used to verify the stability of the results. We also performed a subgroup analysis and mediation effect analysis to control for the influence of confounding factors and analyzed the relationship between the number of abortions and subsequent preterm birth. RESULTS: Our study included 2,985 women who had undergone a prior induced abortion. Women who reported having a prior induced abortion were more likely to have preterm births before 37 weeks and 34 weeks, with risk ratios of 1.18 (95% CI 1.02-1.36) and 1.65 (95% CI 1.23-2.21), respectively. The above associations were stable in all models. We also found that a history of induced abortion was independently associated with a higher risk of preterm birth and early preterm birth in the subgroups. After controlling for the indirect effect of demographic data, the direct effect of abortion history on follow-up preterm delivery was still significantly different. The higher the number of abortions, the greater the risk of subsequent preterm birth. CONCLUSIONS: This study suggests that induced abortion increases the risk of subsequent preterm birth.

History of IUD utilization and the risk of preterm birth: a cohort study.

OBJECTIVE: To explore whether a history of IUD use could increase the risk of subsequent preterm birth. METHODS: We performed a cohort study of 24,496 multipara aged 19-48 years in Dongguan City. Each subject was followed up for 1 year, and 12,508 women obtained pregnancy outcomes. They were divided into 2 groups: 2130 subjects with IUD use history (exposure group), and 10,378 subjects without IUD use history (control group). The exposure group will remove the IUD before pregnancy. The primary outcomes were preterm birth (less than 37 weeks of gestation) and early preterm birth (less than 34 weeks of gestation). We used log-binomial regression to estimate adjusted risk ratios (aRR) of preterm birth and early preterm birth for women with a history of IUD. According to the different adjusted baseline data, three regression models were established, and the propensity matching score method was also used to verify the stability of the results. RESULTS: The delivery rate of women with IUD history was 51.24%, and that of women without IUD was 51.03% (2 = 0.063, P = 0.802). Six hundred and eighty-five women had preterm birth (5.48%, 95% CI 5.08-5.88) and 133 women had early preterm birth (1.06%, 95% CI 0.83-1.24). Compared with the control group, the incidence of preterm birth and early preterm birth in the exposure group were significantly lower. The results are stable in all four models. Subgroup analysis also supported the result. This study also found that the longer the women used IUD before pregnancy, the younger the age of first using IUD, and the shorter the time from condom removal to pregnancy, the lower the incidence of premature birth. CONCLUSION: The women with a history of IUD use are less likely to have premature birth after the IUD is removed. More prospective studies are needed to confirm it.

Elevated serum neurofilament light chain in children autism spectrum disorder: A case control study.

OBJECTIVE: We aimed to assess serum neurofilament light chain (sNfL) levels in autism spectrum disorder (ASD) and to investigate whether they are related to the severity of disease. METHODS: The cohorts consisted of 166 children aged 3-8 (83 children diagnosed with ASD and 83 children with typically-developing). sNfL were analyzed using Single Molecule Array (Simoa) technology. ASD symptom severity was assessed according to the Chinese version of the Childhood Autism Rating Scale (CARS) score. RESULTS: The mean age of those included ASD was 5.1 years (standard deviations [S.D.]: 1.7) and 78.3 % were boys. The mean (SD) sNfL concentrations were significantly (P < 0.001) higher in ASD than in TP children (10.2[5.0] pg/mL and 7.1[3.2]pg/mL). For each 1 pg/mL increase of sNfL, the risk of ASD would increase by 19 % (with the OR unadjusted of 1.19 [95 % CI 1.10-1.29], P < 0.001) and 11 % (with the OR adjusted of 1.11 [1.03-1.23], P < 0.001), respectively. sNfL concentrations in children with severe ASD were higher than in those children with mild-to-moderate ASD (12.4[5.1] pg/mL vs. 8.3[4.2]pg/mL; P < 0.001). Among ASD cases, each 1 pg/mL increase of sNfL is associated with 20 % higher unadjusted or 11 % higher adjusted odds, respectively, of severe (vs. mild-to-moderate) ASD. CONCLUSIONS: The data showed that sNfL was elevated in ASD and related to symptom severity, suggesting that sNfL may play a role in ASD progression.

The effects of preconception examinations on birth defects: a population-based cohort study in Dongguan City, China.

Objective: To evaluate the effect of preconception examinations programs on the prevention of birth defects in Dongguan City during 2013-2017.Methods: The data were from preconception examinations system and the birth defects surveillance system during 2013-2017. The study population included 63,175 infants born to mothers accepted preconception examinations during pregnancy (the screening group) and 649,862 infants whose mother did not check (the control group). The infants included for stillbirth, dead fetus, live birth between 28 weeks of gestation and 7 days after birth and legal pregnancy termination. The risk ratios (RRs) and 95% confidence intervals (CIs) were calculated to examine for the association between birth defects and preconception examinations. We also conducted a stratified analysis based on infant gender and disease classification, and maternal age and region.Results: The incidence of birth defects in the screening group was 134.55/10,000, while that in the control group was 241.53/10,000. Preconception examinations can effectively reduce the incidence of birth defects (BDs) (RR: 0.557, 95%CI: 0.520-0.597). Bifid spine (RR: 0.076, 95%CI: 0.011-0.545), anencephalia (RR: 0.134, 95%CI: 0.033-0.543) and anorectal atresia or stenosis (RR: 0.151, 95%CI: 0.048-0.471) were controlled best, and Down syndrome (RR: 0.684, 95%CI: 0.435-1.075) was no effect. Young maternal age (14-19 years) and old maternal age will increase the risk of birth defects. Preconception examinations had the best effect for pregnant women under 25 years of age (RR: 0.465, 95%CI: 0.387-0.559), and were relatively poor for women aged 30-34 years (RR: 0.678, 95%CI: 0.593-0.776). The incidence of the urban was significantly higher than that of the rural. The effect of preconception examinations to prevent birth defects was more effective in urban areas (RR: 0.453, 95%CI: 0.391-0.525) than in rural areas (RR: 0.577, 95%CI: 0.533-0.625). The incidence of BDs in males was higher than that in females.Conclusions: By implementing preconception examinations project, birth defects in Dongguan have been well controlled. This can provide reference for other developing countries to prevent birth defects.